Project Summary/Abstract Smoking continues to be the leading cause of preventable death in the US and is a major risk factor for developing multiple kinds of cancer. Motivational Interviewing (MI) is a promising intervention that is aimed at helping people quit. However, to date, research examining mechanisms accounting for why MI works has been limited. The present proposal explores whether MI works in part due to its effect on widely-researched psychologicalvariablethathasyettobeappliedtoMI:Cognitivecomplexity.Cognitivecomplexityisthe degree that people see an issue as containing more than one facet. Building on a model of the cognitive complexity-healthy behavior relationship, the present proposal evaluates whether MI works best when it encourages people to transition from high to low levels of cognitive complexity towards smoking by the end of treatment. Preliminary data suggest that, during an MI intervention, client cognitive complexity was lower for persons who ultimately succeeded in quitting smoking compared to those who tried to succeed and failed, and that successful quitters showed a steeper drop in complexity from beginning to end of treatment. Previous findings in other domains have demonstrated that cognitive complexity can be altered. As a result, a focus on cognitive complexity could prove useful for maximizing the effectiveness of MI interventions. The present project has two two aims. Specific Aim 1 is to establish the predictive validity of client cognitive complexity in understanding clients' success or failure during an MI smoking cessation intervention. To accomplish Specific Aim 1, a secondary data analysis is proposed encompassing 240 counseling sessions (4 each from 60 participants) that occurred during an MI intervention for smoking behavior. For each session, researchers will code transcripts of the client's statements for cognitive complexity and compare the complexity of participants who successfully quit smoking with those who tried to quit but failed. Specific Aim 2 is to design and pilot test an intervention aimed at lowering the cognitive complexity of persons towards smoking based on an analysis of the discussions between counselors and clients. To accomplish Specific Aim 2, the present project will design a new complexity-specific MI module via a qualitative analysis of interactions between counselors and clients during MI sessions. Specifically, a grounded theory approach will classify the types of counselor statements that elicit various levels of complexity in clients. This analysis will then be used to construct a brief MI-consistent module designed to lower cognitive complexity. As a final step, the project will subsequently provide an initial pilot test of the effectiveness of this newly-developed module in lowering cognitive complexity on 20 smokers. In accordance with AREA grant objectives, the project activities will incorporate both undergraduate and graduate students.